|Publication number||US4551061 A|
|Application number||US 06/485,654|
|Publication date||Nov 5, 1985|
|Filing date||Apr 18, 1983|
|Priority date||Apr 18, 1983|
|Publication number||06485654, 485654, US 4551061 A, US 4551061A, US-A-4551061, US4551061 A, US4551061A|
|Inventors||Ralph W. Olenick|
|Original Assignee||Olenick Ralph W|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (4), Referenced by (70), Classifications (7), Legal Events (4)|
|External Links: USPTO, USPTO Assignment, Espacenet|
The invention relates to robot arms, and more particularly to a flexible and extensible arm.
Most robot arms of the prior art are rigid. Rigidity is desired for lifting loads having substantial mass and, it has been tought, for accurate positioning of the arm. Most prior art robot arms rely on motors for accurate movement of arm joints. Usually robot arms are formed by a plurality of rigid links connected by joints with motors changing positions of the links, usually by means of gears attached to the links at the joints. Alternatively, exterior hydraulic pistons and cylinders have been used to change the position of one link relative to another link in much the same way as linkages appearing on other industrial equipment, such as earth moving equipment and farm machinery. The most recent robot arms developed utilize servo controlled stepper motors for precise positioning of arm links.
There is a class of robot applications where a rigid arm is not desired. For example, in home uses a rigid arm could be dangerous, especially where small children are present. In other applications, where the object to be manipulated has very low mass, such as a wafer of the type used in integrated circuit fabrication, a rigid arm is simply not needed and could cause damage to a wafer in the event of a positioning error. Since a rigid arm is not intended to give, a positioning error could cause breakage of the wafer by causing it to bump into a fixed object. There is still another class of robots, which may be classified as toys or theatrical robots, which perform under computer control. These robots do not need rigid arms and might be dangerous if so equipped.
Another object of the invention was to devise a non-rigid or semi-rigid robot arm which could bend or extend on command.
The above object has been achieved in a robot arm formed of a plurality of parallel, elongated adjacent elastomeric tubes which form a tube bundle. One end of the tube bundle is adapted for connection to a gripper while the opposite end has an interface for control circuitry. The elastomeric tubes are supplied with differential fluid pressure, pneumatic or hydraulic, to force bending. The tubes are maintained in parallel alignment by means of spaced apart parallel ribs, formed by disks, through which the tubes pass. The ribs form a framework for supporting the tubes, as well for supporting an outer covering for the arm. When differential fluid pressure is applied to the tubes, the arm flexes. If pressure is uniformly increased, the arm extends.
The elastomeric tubes may be constrained against radial expansion by means of helical springs disposed about the tubes. The springs prevent outward bulging of the tubes.
A plurality of flexible rods extend through guide holes in the periphery of the ribs and are fixed at the gripper end of the tube bundle. At the opposite end of the tube bundle, the rods may be inserted into linear electronic position sensors such as an optical position encoder so that the rods, upon flexing of the arms, may be sensed and control circuitry may be provided to adjust differential pressure in the arm. Servo control may be provided using the transducers to generate a position signal which is combined with a command signal. The difference between the command and the position signals is an error signal which may be corrected by applying the proper amount of differential pressure.
FIG. 1 is a top plan view of the robot arm of the present invention with a gripper connected thereto.
FIG. 2 is a sectional view taken along lines 2--2 of FIG. 1 showing degrees of freedom of the robot arm.
FIG. 3 is a top, partially cut-away view of the robot arm of the present invention.
FIG. 4 is an end view taken along lines 4--4 of FIG. 3.
FIG. 5 is a detail of a tube terminating assembly illustrated in FIG. 4.
FIG. 6 is a top plan view of a robot arm of the present invention in a straight position.
FIG. 7 is a top plan view of the present invention in a flexed condition.
With reference to FIG. 1, the robot arm 11 is shown, having a first end 13 connected to a gripper 15 and a second end 17 connected to a fluid pressure supply line 19. The arm is extendible as indicated by dashed lines 21 upon application of a uniform amount of fluid pressure in each of the cylinders or can flex as indicated by the dashed lines 23a and 23b upon application of differential amounts of pressure.
With reference to FIG. 2, the range of motion of the arm 11 is not limited to a single plane. Rather, the range is entirely variable, with possible positions indicated by the dashed lines 25a . . . 25h. The two flexed positions illustrated in FIG. 1 can be achieved by providing two parallel, elongated elastomeric tubes in a tube bundle, with the two tubes maintained in parallel alignment. Then by supplying differential pressure to the two tubes, resembling thick-walled balloons, the motions shown in FIG. 1 may be achieved. If more than two tubes are provided, then a full range of motions, as illustrated in FIG. 1, may be achieved.
FIG. 3 shows a configuration having three parallel elastomeric tubes 31, 33 and 35. These tubes extend through a series of parallel ribs 41, 43, and 45. The tubes are approximately 1.5 centimeters in diameter and are fastened at a first end of the arm 13 in a manner described below. The opposite end of the tubes are secured at end 17 in a similar manner. The tubes have helical springs 47 surrounding their outer surface to prevent radial expansion of the elastomeric tubes. Only lengthwise expansion is desired. The tube material may be sufficiently tough to resist radial expansion or springs may be provided as shown. In order to prevent radial expansion, the tubes may have helically wound fibers of polyester or similar material incorporated in the elastomeric material. This would eliminate the need for exterior springs.
The ribs 41, 43, and 45 have apertures, such as apertures 42, 44 and 46 defined therein. Since each of the ribs 41, 43 and 45 has apertures in corresponding locations, such apertures form a passageway for seating the elastomeric tubes. The passageways are generally parallel such that the tubes may be maintained in generally parallel alignment. Pressure lines 51, 53 and 55 are connected to each of the tubes for introducing the proper amount of fluid pressure. A fluid supply source, not shown, independently supplies each of the lines 51, 53 and 55 under machine control.
In order to ascertain the amount of flexing of the robot arm, a plurality of flexible rods 61, 63 and 65 is disposed about different radial positions of the arm. The rods are fixed at end 13 by means of connection to rib 41. At an opposite end, the rods pass through a linear position sensor 71, 73, and 75. The rods are movable within the sensor with the amount of motion therein being converted into a digital electrical signal. The electrical signal may then be used to gauge the amount of arm flexing or extension. Preferably, the flexible rods are placed at equi-angular peripheral regions of the arm.
A fabric covering 57, resembling a sleeve, is disposed about the ribs 41, 43 and 45 about their circumferential periphery. The sleeve is to protect internal components from dirt and to give the arm a decorative outward appearance. The fabric sleeve may be supported directly on the ribs or may have its own framework consisting of a radial spring 59 slightly exceeding the circumference of the ribs. By providing a separate support structure, the sleeve may have radial dimples which tend to become taut on flexing.
With reference to FIG. 4, the rib 41 is shown terminating tubes 31, 33 and 35. The rib 41 is seen to be a round disk with radial structural reinforcement bosses 42a, 42b . . . 42f. Between these bosses are apertures, including apertures 32, 34 and 36, which partially define passageways for the tubes 31, 33 and 35 respectively. Additionally, apertures 62, 64 and 66 are provided to seat the flexible rods. In rib 41, the flexible rods are held in place with a fastener. In other ribs, the rod may pass therethrough being guided by a linear bearing in that place. Rib 41 also includes apertures 72, 74 and 76 which may allow passage or other control lines therethrough, such as fluid control lines for the robot gripper. Additionally, these apertures serve the function of lightening the weight of the ribs.
FIG. 5 illustrates the termination of a tube in a rib 45 at the second end of the robot arm. The tube has an aperture 32a seating tube 31 and its encircling helical spring. From the back side of rib 45, not shown, a bolt is seated in the tube which is locked in place by means of a nut 77. The shank 79 of the bolt has a central hole 81 drilled therein for allowing fluid pressure to be connected into the interior of the tube. A washer 83 seals the end of the tube and rests against the spring. Washer 83 is pushed inwardly by tightening nut 77 and forms an expansion fluid seal against both the elastomeric tube material and the spring.
Hole 81 may be threaded to seat a hollow threaded adaptor which fits into these threads on one end and on another end connects to a fluid supply line.
The flexible rod 61 is shown extending through rib 45 through aperture 62. The operation of the rod is explained below.
With reference to FIGS. 6 and 7, a robot arm 11 is shown having an interface 13 for mounting a gripper or other tool. At an end of the arm opposite the interface, transducers 71, 73 and 75 are connected. Flexible rods 61, 63 and 65, supported by parallel ribs 41, 43 . . . 45. The parallel rods also add rigidity to the flexible arm. In FIG. 6 the rods are shown to extend the same amount into respective transducers. As the amount of fluid is varied into the tubes, flexing of the arm occurs as illustrated in FIG. 7. This causes a change in position of the rods with rod 61 moving in the direction indicated by the arrow A, rod 63 moving in the direction indicated by arrow B, and rod 65 moving in the direction indicated by arrow C. Since the position of the transducers is known, and since motion of the rods within the transducer is converted to an electrical signal proportional to the amount of rod motion, the extent of flexing of the arm may be computed. Transducers that convert the position of the rods to a proportional electrical signal are well known. For example, a linear variable differential transformer (LVDT) could be used. See Handbook of Measurement and Control, rev. ed., Pennsauken, N.J.: Schaevitz Engineering (1976).
The motion reported by transducers 71, 73 and 75 represents the actual arm position. Usually, an arm is directed to a particular target by means of a command signal. Any difference between the command signal and the reported actual position represents an error signal. The error may be reduced to zero by means of a conventional closed loop servo system which is connected to the fluid control supply. Whenever an error is reported, fluid is injected or removed from appropriate tubes in order to correct arm position for zero positional error. Instead of a closed loop servo system, as described, an open loop system may also be used where the arm is merely directed to a desired position by providing needed amounts of fluid to the various tubes.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US1590919 *||Jul 5, 1924||Jun 29, 1926||of brooklyn|
|US3284964 *||Mar 26, 1964||Nov 15, 1966||Norio Saito||Flexible beam structures|
|US4218166 *||Nov 24, 1978||Aug 19, 1980||General Motors Corporation||Guide device for multi-axis manipulator|
|EP0017016A1 *||Mar 10, 1980||Oct 15, 1980||Robotgruppen HB||Flexible arm, particularly a robot arm|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US4712969 *||Aug 24, 1984||Dec 15, 1987||Kabushiki Kaisha Toshiba||Expandable and contractable arms|
|US4765795 *||Jun 10, 1986||Aug 23, 1988||Lord Corporation||Object manipulator|
|US4784042 *||Feb 10, 1987||Nov 15, 1988||Nathaniel A. Hardin||Method and system employing strings of opposed gaseous-fluid inflatable tension actuators in jointed arms, legs, beams and columns for controlling their movements|
|US4792173 *||Oct 30, 1987||Dec 20, 1988||Duke University||Fluid actuated limb|
|US5218280 *||May 19, 1989||Jun 8, 1993||Edwards Eric F R||Movement actuators|
|US5297443 *||Jul 7, 1992||Mar 29, 1994||Wentz John D||Flexible positioning appendage|
|US5317952 *||Dec 14, 1992||Jun 7, 1994||Kinetic Sciences Inc.||Tentacle-like manipulators with adjustable tension lines|
|US5401069 *||May 4, 1993||Mar 28, 1995||The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration||Inflatable rescue device|
|US5692412 *||Apr 23, 1996||Dec 2, 1997||Ross-Hime Designs, Incorporated||Robotic manipulator|
|US5758917 *||Aug 29, 1995||Jun 2, 1998||Langley; John Charles Mark||Dog faeces collector|
|US6858005||Aug 27, 2002||Feb 22, 2005||Neo Guide Systems, Inc.||Tendon-driven endoscope and methods of insertion|
|US8002365||Nov 13, 2007||Aug 23, 2011||Raytheon Company||Conformable track assembly for a robotic crawler|
|US8002716||May 7, 2008||Aug 23, 2011||Raytheon Company||Method for manufacturing a complex structure|
|US8042630||Jun 22, 2010||Oct 25, 2011||Raytheon Company||Serpentine robotic crawler|
|US8062212||May 13, 2005||Nov 22, 2011||Intuitive Surgical Operations, Inc.||Steerable endoscope and improved method of insertion|
|US8083879||Nov 22, 2006||Dec 27, 2011||Intuitive Surgical Operations, Inc.||Non-metallic, multi-strand control cable for steerable instruments|
|US8116886||Oct 16, 2006||Feb 14, 2012||The Trustees Of Columbia University In The City Of New York||Electrode arrays and systems for inserting same|
|US8126591 *||Dec 20, 2007||Feb 28, 2012||Oliver Crispin Robotics Limited||Robotic arms|
|US8182418||Feb 25, 2008||May 22, 2012||Intuitive Surgical Operations, Inc.||Systems and methods for articulating an elongate body|
|US8185241||Nov 13, 2007||May 22, 2012||Raytheon Company||Tracked robotic crawler having a moveable arm|
|US8205695||Apr 22, 2010||Jun 26, 2012||Raytheon Company||Conformable track assembly for a robotic crawler|
|US8317555||Jun 11, 2010||Nov 27, 2012||Raytheon Company||Amphibious robotic crawler|
|US8361090||Feb 7, 2008||Jan 29, 2013||Intuitive Surgical Operations, Inc.||Apparatus and method for endoscopic colectomy|
|US8392036||Jan 8, 2009||Mar 5, 2013||Raytheon Company||Point and go navigation system and method|
|US8393422||May 25, 2012||Mar 12, 2013||Raytheon Company||Serpentine robotic crawler|
|US8434208||Jul 12, 2011||May 7, 2013||Raytheon Company||Two-dimensional layout for use in a complex structure|
|US8517923||May 19, 2004||Aug 27, 2013||Intuitive Surgical Operations, Inc.||Apparatus and methods for facilitating treatment of tissue via improved delivery of energy based and non-energy based modalities|
|US8568299||May 18, 2007||Oct 29, 2013||Intuitive Surgical Operations, Inc.||Methods and apparatus for displaying three-dimensional orientation of a steerable distal tip of an endoscope|
|US8571711||Jul 10, 2008||Oct 29, 2013||Raytheon Company||Modular robotic crawler|
|US8608647||Apr 24, 2012||Dec 17, 2013||Intuitive Surgical Operations, Inc.||Systems and methods for articulating an elongate body|
|US8641602||Jun 28, 2012||Feb 4, 2014||Intuitive Surgical Operations, Inc.||Steerable endoscope and improved method of insertion|
|US8696694||Dec 28, 2012||Apr 15, 2014||Intuitive Surgical Operations, Inc.||Apparatus and method for endoscopic colectomy|
|US8721530||Jul 11, 2011||May 13, 2014||Intuitive Surgical Operations, Inc.||Tendon-driven endoscope and methods of use|
|US8758232||Dec 27, 2010||Jun 24, 2014||Oliver Crispin Robotics Limited||Robotic arm|
|US8827894||Oct 27, 2011||Sep 9, 2014||Intuitive Surgical Operations, Inc.||Steerable endoscope and improved method of insertion|
|US8834354||May 13, 2005||Sep 16, 2014||Intuitive Surgical Operations, Inc.||Steerable endoscope and improved method of insertion|
|US8845524||Nov 19, 2010||Sep 30, 2014||Intuitive Surgical Operations, Inc.||Steerable segmented endoscope and method of insertion|
|US8863608 *||Dec 14, 2010||Oct 21, 2014||Festo Ag & Co. Kg||Fluid-operated manipulator|
|US8882657||Dec 28, 2006||Nov 11, 2014||Intuitive Surgical Operations, Inc.||Instrument having radio frequency identification systems and methods for use|
|US8888688||Nov 12, 2004||Nov 18, 2014||Intuitive Surgical Operations, Inc.||Connector device for a controllable instrument|
|US8935014||Jun 11, 2010||Jan 13, 2015||Sarcos, Lc||Method and system for deploying a surveillance network|
|US9031698||Oct 31, 2012||May 12, 2015||Sarcos Lc||Serpentine robotic crawler|
|US9072427||Dec 22, 2011||Jul 7, 2015||Intuitive Surgical Operations, Inc.||Tool with articulation lock|
|US9085085||Aug 28, 2013||Jul 21, 2015||Intuitive Surgical Operations, Inc.||Articulating mechanisms with actuatable elements|
|US9138132||Jan 6, 2014||Sep 22, 2015||Intuitive Surgical Operations, Inc.||Steerable endoscope and improved method of insertion|
|US9220398||Oct 11, 2007||Dec 29, 2015||Intuitive Surgical Operations, Inc.||System for managing Bowden cables in articulating instruments|
|US9357901||Sep 27, 2013||Jun 7, 2016||Intuitive Surgical Operations, Inc.||Methods and apparatus for displaying three-dimensional orientation of a steerable distal tip of an endoscope|
|US9370868||Apr 23, 2010||Jun 21, 2016||Intuitive Surgical Operations, Inc.||Articulating endoscopes|
|US9409292||Sep 13, 2013||Aug 9, 2016||Sarcos Lc||Serpentine robotic crawler for performing dexterous operations|
|US9421016||Mar 6, 2014||Aug 23, 2016||Intuitive Surgical Operations, Inc.||Apparatus and method for endoscopic colectomy|
|US9427282||Aug 8, 2013||Aug 30, 2016||Intuitive Surgical Operations, Inc.||Apparatus and methods for facilitating treatment of tissue via improved delivery of energy based and non-energy based modalities|
|US9434077 *||Apr 23, 2010||Sep 6, 2016||Intuitive Surgical Operations, Inc||Articulating catheters|
|US9440364||Apr 23, 2010||Sep 13, 2016||Intuitive Surgical Operations, Inc.||Articulating instrument|
|US9498888||Apr 24, 2008||Nov 22, 2016||Intuitive Surgical Operations, Inc.||Articulating instrument|
|US20060156851 *||Dec 1, 2005||Jul 20, 2006||Jacobsen Stephen C||Mechanical serpentine device|
|US20070132722 *||Oct 27, 2006||Jun 14, 2007||Electronics And Telecommunications Research Institute||Hand interface glove using miniaturized absolute position sensors and hand interface system using the same|
|US20070225787 *||Oct 16, 2006||Sep 27, 2007||Nabil Simaan||Electrode arrays and systems for inserting same|
|US20080154288 *||Feb 7, 2008||Jun 26, 2008||Neoguide Systems, Inc.||Apparatus and method for endoscopic colectomy|
|US20080161971 *||Dec 20, 2007||Jul 3, 2008||Robert Oliver Buckingham||Robotic Arms|
|US20110174108 *||Dec 27, 2010||Jul 21, 2011||Andrew Crispin Graham||Robotic arm|
|US20120210818 *||Dec 14, 2010||Aug 23, 2012||Festo Ag & Co. Kg||Fluid-Operated Manipulator|
|US20130090763 *||Jan 26, 2009||Apr 11, 2013||The Trustees Of Columibia University In The City Of The City Of New York||Systems and methods for force sensing in a robot|
|US20130091974 *||May 31, 2011||Apr 18, 2013||Commissariat A L'energie Atomique Et Aux Energies Alternatives||Articulated inflatable structure and robot arm comprising such a structure|
|CN102896633A *||Sep 27, 2012||Jan 30, 2013||浙江大学||Flexible spine with omni-directional angle feedback|
|CN102896633B *||Sep 27, 2012||May 27, 2015||浙江大学||Flexible spine with omni-directional angle feedback|
|DE102014113962B3 *||Sep 26, 2014||Dec 10, 2015||Gottfried Wilhelm Leibniz Universitšt Hannover||Arbeitsmechanismus|
|EP0341953A1 *||May 8, 1989||Nov 15, 1989||THE BABCOCK & WILCOX COMPANY||Search and retrieval device|
|EP0654327A1 *||Nov 8, 1994||May 24, 1995||Siemens Aktiengesellschaft||Device and method for determining the variable length of a cable guided in an actuator|
|WO2006136827A1 *||Jun 21, 2006||Dec 28, 2006||Oliver Crispin Robotics Limited||Robotic arm comprising a plurality of articulated elements and means for determining the shape of the arm|
|WO2016045658A1||Aug 25, 2015||Mar 31, 2016||Gottfried Wilhelm Leibniz Universitšt Hannover||Working mechanism|
|U.S. Classification||414/735, 901/21, 901/9, 73/431|
|Apr 22, 1986||CC||Certificate of correction|
|Jun 6, 1989||REMI||Maintenance fee reminder mailed|
|Nov 5, 1989||LAPS||Lapse for failure to pay maintenance fees|
|Jan 23, 1990||FP||Expired due to failure to pay maintenance fee|
Effective date: 19891105